TEXT OF THE DESCRIPTION
The present invention concerns electric power generators for motor vehicles and, more specifically, to an alternator generator having an electronic regulator.
It is known that the voltage regulator of an alternator senses the output voltage of the alternator and acts upon the excitation current of the alternator in order to maintain the output voltage within predetermined limits. Overvoltage conditions, however, may occur, under which not only is the regulator ineffective, but may itself be damaged, such as, for example, in the case of the accidental disconnection or breaking of the cable connecting the alternator to the load consisting of the motor vehicle battery and other electric or electronic devices. In order to avoid damage, which is particularly likely if the regulator is constructed as an integrated circuit, it is necessary to apply appropriate limiting devices to the output of the alternator and/or to resort to manufacturing technology used for high-voltage integrated circuits. A less serious condition in absolute terms, but more dangerous because it also affects the devices and circuits powered by the generator, may occur when the battery connection is accidentally disconnected, while the other loads remain connected to the alternator. The reason is that, if the battery was being charged a moment before the disconnection thereof, and therefore the current absorbed by it was considerable, the overvoltage may be sufficiently high to damage some device powered by the alternator. In order to avoid this risk as well, if a limiting device of adequate power is not already provided for the output of the alternator, it is necessary to protect each device individually. Specifically, if said devices are built as integrated circuits, often it is necessary again to resort to overvoltage-resistant structures.